Press



Nov. 19, 1940. v MEYER 2,221,877' I PRESS Filed Oct. 27, 1939 4 Sheets-Sheet 1 Nov. 19, 1940. v, MEYER PRESS 4 Sheets-Sheet 2 Filed Oct 27, 1939 Nov 19, 1940. v. H. MEYER 2,221,877

PRESS Filed Oct. 27, 1959 4 Sheets-Sheet 3 Patented Nov. 19, 1940 PRESS Vernon H. Meyer, Beverly, Mass, assignor to United Shoe Machinery Corporation, Borough of Flemington, N. J;

Application October 27,, 1939, Serial No. 301,655

21 Claims.

This invention relates to improvements in presses and is illustrated herein as embodied in a clicking machine of the type disclosed in Letters Patent of the United states No. 921,503 is- 5 sued May 11, 1909, on an application of Arthur Bates, and adapted to force a cutting die through a piece of sheet material such as leather.

Such machines are generally constructed with a presser member which is mounted for horizontal swinging movement on a vertical post. On actuation of a starting mechanism, the post is moved downwardly carrying the presser member toward a table or work support on which rests the sheet material being operated upon. A die has previously been positioned on the material and the blow struck the die by the presser member, as the latter moves downwardly, forces the die through the sheet material. In such machines, particular- 1y when used on fibrous material such as leather, it is desirable that the presser member should have a high striking velocity in order to drive the die through the material cleanly. A low velocity combined with a heavy pressure which presses the die through the sheet material rather than driving it through frequently results in rough,

furry edges particularly on the under side of the material, so that the effect is somewhat similar to that which would be obtained if the material were cut halfway through and then torn to com- 39 plete the severing operation. Edges of this nature cause difficulty if further operations are to be performed on them. The customary driving means in such machines, however, is an eccentric which is connected by a strap to the presser member. Due to the nature of eccentric movement, the presser member decelerates after it has completed the first half of its downward movement, and since the moment of impact on the die occurs well toward the bottom of the stroke, the presser member is moving very slowly at this point.

It is, accordingly, desirable to speed up the presser member at that portion of its cycle in which the stock is actually being cut, that is, toward the end of the downward movement of the beam. Simply rotating the drive shaft at a higher rate of speed is not satisfactory, since the presser member will still decelerate during the second half of its downward movement and any permissible increase in the speed of the drive shaft will be insufficient to efiect the desired improvement in the cutting operation. There is, furthermore, no advantage in increasing the speed at which the F presser member returns to its starting position. On the contrary, this results in increasing the jar occurring when the presser member stops at the top of its stroke.

With these considerations in view, it is an object of the present invention to improve the qualtity of the work done by machines of this type by in- 5 creasing the striking velocity of the presser member without speeding up the flywheel of the machine and without altering the distance through which the beam moves during a complete reciprocation thereof. Accordingly, the invention contemplates modifying the cycle of reciprocation of thepresser member by speeding it up at that portion of the cycle immediately prior to the point at which the cutting starts so as to increase the momentum of the beam andthereby increase the cutting power available from that source.

The invention will be more fully understood when considered in relation to the accompanying drawings, in which Fig. 1 is a side elevation ing the invention;

Fig. 2 isa sectional view of the piston and the forward end of the drive shaft;

Fig. 3 is a view, partly in section, of the fiywheel and clutch Fig. 4 is a cross section along the line IV-IV of Fig. 3;

Fig. 5 is a cross section of the clutch ring and case;

Fig. 6 is a View, partly in section, substantially along the line VIVI of Fig. 1; and

I Fig. 7 is an isometric view of the brake applying members. y

The invention is illustrated as embodied in a machine of the type disclosed in the above-mew tioned Letters Patent No. 921,503. As illustrated in Fig. 1, the machine comprises a presser member ll] mounted on a post l2 for horizontal swinging movement above a work support It. The post is vertically reciprocable in a frame It and is connected by a link I8 to an eccentric 2!] on a shaft 22 journaled in the lower part of the frame. A flywheel 24 adapted to be driven by a belt or an electric motor (not shown) is loosely mounted on the shaft and is arranged to be connected therewith by a clutch in a manner to be described in detail subsequently.

As has already been pointed out, it is desirable to drive the presser member at an increased speed during that portion of its cycle of movement when it is descending toward the work support. To this end there is provided a cylinder 26 fastened by bolts 28 to the frame adjacent to the forward end of the shaft. Referring now to Fig. 2, the cylinder is bored to receive a piston 30 which is slidable of a machine embody- 20 vertically in the cylinder. At the end of the shaft 22 is a crank 32 and to it a connecting rod 34 is tied, a roller bearing 36 being provided to reduce friction to a minimum. The lower end of the connecting rod 34 is secured to the piston by a wrist pin 38. It is to be noted that the high sides of the crank 32 and the eccentric 20 (Fig. 2) are diametrically opposed on the shaft so that the presser member is moving toward the work support when the piston is rising.

The actuating force of the piston is the air or other gas confined under high pressure in a chamber 40 formed between the cylinder head 42 and the dished head 44 of the piston. Thus, as soon as the rotation of the shaft moves the crank out of alinement with the connecting rod, the compressed gas forces the piston upwardly thereby causing the presser member to move downwardly.

It is desirable, however, to maintain the force applied to the piston at as constant a level as possible rather than to permit it to decrease toward the end of the stroke. For this purpose the cylinder head 42 is bored and threaded to receive a pipe 46, which leads to an auxiliary air chamber 48 (Fig. 1) provided with an inlet valve 50 through which air may be forced to maintain the pressure at the desired level. The pipe 46 permits air to pass freely between the auxiliary chamber 48 and the pressure chamber 40 so that, in effect, the volume of the pressure chamber is substantially increased, thereby reducing the proportional change in volume of gas in the pressure chamber as the piston moves upwardly. Since the change in pressure is inversely proportional to the change in volume, the auxiliary chamber keeps the air at a more nearly constant pressure.

Because of the weight of the parts operated by the piston, the air pressure in the chamber must be kept high in order that the force driving the piston will be sufiicient to accelerate the presser member to a substantial extent. This is. especially true in view of the fact that the force of the blow struck the die in this manner is dependent upon the weight and velocity of the presser member, since the pressure of the air contributes very little additional force. The maximum practical acceleration must be obtained in order for the machine to operate most efficiently. For most purposes a minimum pressure of approximately eighty pounds per square inch should be provided. With such a pressure and a piston diameter of about seven inches the presser member is accelerated to a velocity of about three feet per second, as compared to a velocity of about one foot per second imparted to it by the flywheel alone.

It will, of course, be realized that the compressed gas will tend to leak out between the cylinder walls 52 and the skirt 54 of the piston, To reduce this leakage two piston rings 56 are provided and in addition the cylinder head forms a reservoir which is partially filled with oil 58 which seals the space between the cylinder wall and the skirt of the piston. To return the oil which escapes and collects in the hollowed out central portion of the reservoir a pump 60 is provided. This pump is conveniently of the positive displacement type and is operated by the striking of its plunger 62 against an abutment 63 on the frame.

Inasmuch as the flywheel 24 rotates at a constant rate of speed, it will be obvious that the means by which the flywheel is connected to the shaft must permit the latter to rotate at a greater speed than the flywheel in order that the piston may effectively drive the shaft at an increased velocity during the downward movement of the presser member. To meet these requirements there is provided a Horton type overrunning clutch which relies for its holding power on a number of rolls arranged about a shaft in such a manner that they may wedge into the angle formed between the two converging surfaces of a driving and a driven member. Referring now to Figs. 3, 4, and 5, the clutch comprises a clutch ring I4 which is made rigid with the drive shaft by a key I6. The outer portion of the clutch ring carries a number of teeth 18 which project into an annular recess let into the side of the flywheel and co-axial therewith. Positioned between the teeth IB are a number of blocks 82 the outer surfaces of which are curved to correspond with the wall of the recess 80 in the flywheel. Springs 84 tend to hold these blocks in position. The clutch ring I4 is also recessed to receive an annular ring or cage 86. The ring 86 is rotatable slightly within the clutch ring and has teeth 88 which extend into the annular recess in the flywheel and underlie the teeth I8 on the clutch ring 14. Positioned in the slots between the teeth 88 are a number of rolls 92 which are lightly urged in the direction of rotation by spring pressed pins 94. A ring 96 fastened to the clutch ring teeth I8 by screws 98 prevents axial movement of the rolls.

It will be noted that the inner surfaces of the blocks 82 are at a slight angle so that the leading edge I06 is closer to a clutch ring bushing I02 than the trailing edge I44. When the rolls are urged in the direction of rotation, they wedge between the inner surfaces of the blocks and the clutch ring bushing I02 which is keyed at I06 to the flywheel and a flywheel bushing I08 and form a driving connection between the flywheel and the shaft.

In order to throw the rolls into engagement with the blocks and thus cause the flywheel to drive the shaft, there is provided a lever IIfl (Figs. 3, 4, and 6) which is pinned to the roll cage 86 at H2. The end II4 of the lever is slotted to fit over a pin H6 in the clutch ring I4, and a spring H8 connecting the lever H0 and a hook I 20 bolted to the clutch ring tends to pull the lever in the direction of rotation of the clutch ring. The pull on the lever causes the roll cage 86 to move slightly in the direction of rotation, thus allowing the rolls 92 to be moved into engagement with the blocks 82 by the rotating clutch ring bushing Ill2. A bolt I22 limits the movement of the lever H0 and insures that the cage 86 will be so positioned, when the clutch is in engagement, that the rolls 92 will be in the center of the slots in which they are carried. The outer end I24 of the lever Ill) carries a roll I26 so that the clutch will be disengaged when the roll is forced inwardly.

Cooperating with the clutch there is provided mechanism for starting and stopping the machine. As shown in Figs. 1 and 6, a handle I28 on the presser member I ll is connected to a lever I38 pivoted on the frame at I32 and arranged to raise a rod I34. The rod is connected to one arm I36 of a bell crank lever I38 pivoted on a shaft I40 journaled in two hangers I42 depending from the frame. The other arm I44 of the bell crank lever is connected to a rod I46 which extends forwardly to a brake latch I48. The brake latch I48 is pivoted on a pin I50 in a member I52 hav- 1 I60 by a spring I16.

ing a forwardly projecting lug I54 which is slidable in a groove I55 in the rear wall of the cylinder. Near its lower extremity the brake latch has a shoulder I53 arranged to engage one end of a brake lever I58 pivoted on the shaft I 4|], the other end of the brake lever being pivotally connected to a brake arm I62. To the brake arm I62 is bolted one end of a brake strap I64 which extends around a brake drum I 66 (Fig. 3) and is riveted at its other end to the frame at I68. The upper end of the brake arm IE2 also carries an abutment I10 which when the machine is in stopped position engages the roll I26 onthe disengaging lever of the clutch and holds it in disengaged position. Thus when the handle I28 is depressed the rod I46 moves forward permitting the brake lever to drop off the shoulder I58, thereby releasing the brake and raising the abutment I10 so as to permit the spring I I8 to pull the lever I I0 into engaging position.

In order to provide means for stopping the machine at the end of one revolution, the member I52 is connected by means of a strap I12 (Figs. 1 and 7') to an eccentric I14 rigid with the :shaft 22. Thus when the brake lever is dropped the shaft rotates the ecentric I14 carrying the member I52 and the brake latch I48 downwardly until the shoulder I58 is in a position to be pulled rearwardly into engagement with the brake lever As the shaft continues to rotate and the eccentric I14 returns to its starting position, the forward end of the brake lever is carried upward, thereby pulling the brake arm downward to tighten the brake strap IM, and dropping the abutment I10 to a position where it will strike the roll I26 and disengage the clutch.

As a means of further insuring that the shaft will stop after one rotation thereof and for preventing accidental starting of the machine, there is provided an arm I18 rigid with the lever I68. A pin I 89 (Fig. 3) in the upper end of the arm I18 enters an aperture in a slide I82 carried in a recess in the frame. When the starting handle I28 is in normal or raised position the slide I82 projects rearwardly to engage a lug I 84 on the clutch ring and thus prevent the shaft and the clutch from rotating. When the handle is depressed, however, the arm moves forward as the brake is released and moves the slide out of engagement with the lug.

To operate the machine the operator places a piece of sheet material on the cutting block or work support I 5 and sets a die on it in the desired position. He then grasps the presser member, swings it into position over the die, and depresses the handle, thus connecting the flywheel to the shaft. As the shaft 22 rotates, the crank 32 and the connecting rod 35 are moved out of alinement so that the force of the gas in the pressure chamber may become effective. Since the flywheel need give the shaft only a slight starting impulse and subsequently should be disengaged from the shaft to permit the weight of the presser member and the driving force of the piston to carry the presser member downwardly, there is provided an abutment 586 (Fig. 6) upon the frame which is so positioned that it strikes the disengaging lever I Ifi after the shaft has rotated a few degrees. Upon actuation of the disengaging lever by the abutment I85 the shaft is free to rotate at whatever speed may be attained through the combined forces of the piston and the weight of the presser member.

It is to be noted here that since the clutch ring 'and the blocks 82 carried therein are at this point rotating at a higher rate of speed than the clutch ring bushing I02, the rolls 92 have no opportunity to wedge in between the blocks and the clutch ring bushing. However, when the presser member has reached the bottom of its stroke and the force of the piston has carried the crank to its upmost position, the shaft slows down to a speed equal to or less than that of the flywheel. Since the clutch ring bushing is at this point rotating as fast as or faster than the clutch ring and the blocks 82, the rolls 92 are carried by the bushing into engagement with the blocks, and wedged tightly to form a driving connection between the flywheel and the shaft. .The spring pressed pins 94 hold the rolls during the downward portion of the movement of the presser member in such a position that when the flywheel is connected to the shaft at the bottom of the stroke the connection is formed through all the rolls equally rather than having the entire force exerted on a single roll. 1

As the flywheel continues to rotate, the presser member is carried to its upmost position and the piston returns to its lower position. In the course of the pistons movement it, of course, recompresses the air in the pressure chamber so that it is ready to drive the piston when the handle is again depressed.

It will thus be seen that through the medium of the pneumatically driven piston and the overrunning clutch there is provided an effective means for speeding up the movement of the presser member during the downward portion of its cycle of operation without materially increasing the amount of jarring caused by the sudden stopping of the presser member when it has completed its cycle of operation.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A press comprising a work support, a presser member reciprocable toward and from said work support, driving means for said presser member operated from a power shaft, and additional driving means constructed and arranged to move said presser member toward said work support at an increased speed during the later portion of the approach of the presser member toward the work support.

2. A press comprising a work support, a presser member reciprocable toward and from said work support, power-operated means for driving said presser member during one portion of its reciprocatory movement, and supplementary pneumatic driving means for moving said presser member at an increased speed during the later portion of its approach toward the work support.

3. A press comprising a presser member, a work support, means including an eccentric for moving said presser member toward and away from said work support, means for driving said eccentric, an overrunning clutch connecting said driving means and said eccentric, and supple-- mentary pneumatic driving means for driving said presser member at increased speed during the later portion of its movement toward said work support.

4. A press comprising a presser member, a work support, means including an eccentric for moving said presser member toward and awayfrom said work support, means for driving said eccentric, and supplementary pneumatically driven means for driving said presser member at 7 increased speed during the later portion of its movement toward said work support.

5. A press comprising a work support, a presser member reciprocable toward and away from said work support, driving means for imparting an initial impulse to said presser member at the beginning of its movement toward said work support, and pneumatic means for driving said presser member toward said work support during a subsequent portion of each reciprocation, said initial driving means being constructed and arranged to complete said reciprocation of said presser member.

6. A press comprising a presser member, a work support, a shaft, an eccentric rigid with said shaft and constructed and arranged to move said presser member toward and away from said work support, means for rotating said shaft, and supplementary pneumatic means for rotating said shaft at increased speed during the later portion of the movement of said presser member toward said work support.

'7. A press comprising a work support, a presser member, a shaft, means including an eccentric mounted on said shaft for moving said presser member toward and away from said work support, means for rotating said shaft, and means including a power driven piston constructed and arranged to drive said presser member during the later portion of its movement toward said work support.

8. A press comprising a presser member, a work support, a shaft, means for rotating said shaft, an eccentric rigid with said shaft and constructed and arranged to impart to said presser member a cycle of operation comprising movement toward and from said work support, a pneumatically actuated reciprocating piston, and means for converting the reciprocatory movement of said piston into rotary movement and transmitting said rotary movement to said shaft, said shaft rotating means being constructed and arranged to impart an initial impulse to said shaft at the beginning of the movement of the presser member toward the work support, and said piston and said converting means being constructed and arranged to drive said shaft during the remaining portion of the movement of said presser member toward said work support.

9. A press comprising a presser member, a work support, a cylinder, a piston reciprocating in said cylinder and actuated in one direction by a gas confined in said cylinder under high pressure, a shaft, an eccentric rigid with said shaft and constructed and arranged to start movement of said presser member toward said work support, and driving means for rotating said shaft, said piston being constructed and arranged to drive said shaft during the later portion of the movement of the presser member toward said work support, the driving means for said shaft being constructed and arranged to return said presser member and said piston to their respective starting positions.

10. A press comprising a presser member, a work support, a cylinder, a piston reciprocating in said cylinder and actuated in one direction by a gas confined in said cylinder under high pressure, a shaft, an eccentric rigid with said shaft and constructed and arranged to start movement of said presser member toward said work support, and driving means for rotating said shaft, said piston being constructed and arranged to drive said presser member during the later portion of its movement toward the work support, the driving means for said shaft being constructed and arranged to return said presser member and said piston to their respective starting positions.

11. In a press, a presser member, a work support, a shaft, an eccentric mounted on said shaft and constructed and arranged to move said presser member toward and from said work support, driving means for said shaft, a clutch for connecting said driving means to said shaft, means arranged to disengage said clutch within the first 25 of rotation of said shaft, and. pneumatic means for driving said shaft at increased velocity during the later portion of the movement of said presser member toward said work support, said clutch being constructed and arranged to reconnect said driving means to said shaft at the end of the movement of said presser member toward said work support.

12. In a press, a work support, a presser member, driving means for reciprocating said presser member toward and from said work support, additional driving means constructed and arranged to move said presser member toward said work support at an increased rate of speed during a portion of each cycle of operation of the press, and a clutch cooperating with said first driving means, said clutch being constructed and arranged to overrun thereby permitting said additional driving means to operate said presser member at a higher speed than that of said firstmentioned driving means.

13. In a press, a work support, a presser member, a shaft, an eccentric on said shaft constructed and arranged to move said presser member toward and from said support, means for rotating said shaft, an overrunning clutch constructed and arranged to connect said rotating means to said shaft, and a piston for driving said shaft at a speed greater than that of said rotating means during the later portion of the movement of said presser member toward said support.

14. In a press, a presser member, a work support, a shaft, an eccentric mounted on said shaft and constructed and arranged to move said presser member toward and from said work support, means for rotating said shaft, additional means for rotating said shaft to move said presser member toward said work support at a greater velocity during the later portion of each cycle of operation of the press, a clutch for connecting said first-mentioned shaft-rotating means to said shaft, a disengaging lever carried by said clutch, and means for actuating said disengaging lever at the end of one revolution of said shaft.

15. In a press, a presser member, a work support, a shaft, an eccentric mounted on said shaft and constructed and arranged to move said presser member toward and from said work support, means for rotating said shaft, pneumatic means for rotating said shaft at increased velocity 'during movement of said presser member toward said work support, an overrunning clutch, a lever carried by said clutch and constructed and arranged to engage and disengage said clutch, means for actuating said lever to cause said clutch to engage, and means for causing said lever to disengage said clutch after one revolution of said shaft.

16. In a press, a presser member, a work support, a shaft, an eccentric mounted on said shaft and constructed and arranged to move said presser member toward and away from said work support, means for rotating said shaft, separate pneumatic means for rotating said shaft at increased speed during the later portion of the movement of said presser member toward said work support, an overrunning clutch for connecting said rotating means with said shaft, a lever constructed and arranged yieldably to hold said clutch in engaging position, means for holding said lever in disengaged position, means for releasing said lever thereby to cause said clutch to connect said rotating means to said shaft, and an abutment constructed and arranged to cause said lever to disengage said clutch within the first 25 of rotation of said shaft, said lever releasing means being constructed and arranged to cause said lever to disengage said clutch at the end of one revolution of said shaft.

17. In a press, a presser member, a work support, a shaft, an eccentric on said shaft constructed and arranged to move said presser member toward and away from said work support, means for rotating said shaft, additional means constructed and arranged to rotate said shaft to drive said presser member at increased speed during the later portion of movement toward said work support, and means for stopping said shaft after one rotation thereof.

18. In a press, a presser member, a work support, a shaft, means for rotating said shaft, an eccentric mounted on said shaft and constructed and arranged to move said presser member toward and from said work support, a crank on said shaft, a cylinder, a piston slidable in said cylinder and constructed and arranged to be actuated during the movement of said presser member toward said Work support by a gas confined in said cylinder under high pressure, a member connecting said piston to said crank, a reservoir in said cylinder for oil thereby to prevent leakage of said compressed gas, and automatic means for returning escaped oil to said reservoir.

19. In a press, a presser member, a work support, a shaft, means for rotating said shaft, an eccentric mounted on said shaft and constructed and arranged to move said presser member toward and from said work support, a crank on said shaft, a cylinder, a piston slidable in said cylinder and constructed and arranged to be actuated during the later portion of the movement of said presser member toward said work support by a gas confined in said cylinder under high pressure, a member connecting said piston to said crank, a reservoir in said cylinder containing oil for reducing leakage of said gas from said cylinder, said piston being hollow to collect oil escaping from said cylinder, and a pump carried in said piston and constructed and arranged to force oil collected in said piston into said reservoir.

20. In a press, a presser member, a work support, a shaft, means for rotating said shaft, an eccentric rigid with saidshaft and constructed and arranged to move said presser member toward and from said work support, a crank on said shaft, a cylinder, a piston slidable in said cylinder, said piston and said cylinder forming a pressure chamber and being constructed and arranged to be actuated during the movement of said presser member toward said work support by a gas confined in said pressure chamber, and means for maintaining the pressure of the gas in said pressure chamber at a substantially constant level during the movement of said piston.

21. In a press, a presser member, a work support, a shaft, means for rotating said shaft, a cam on said shaft constructed and arranged to move said presser member toward and from said work support, a crank on said shaft, a cylinder, a piston slidable in said cylinder and connected to said crank, said piston and said cylinder forming a pressure chamber and being constructed and arranged to be actuated during the movement of said presser member toward said work support by a gas confined in said pressure chamber, and an auxiliary pressure chamber connected to said cylinder whereby the pressure of the gas in said pressure chamber will remain substantially constant during movement of said piston in said cylinder.

VERNON H. MEYER. 

